1. Field of the Invention
The present invention relates to a power window system, more particular to a power window system that moves a window glass in opening and closing directions in response to operation of a single switch.
2. Related Art
Recently, a power window system has been proposed, in which a remote control single switch operates a window glass to move in opening and closing directions. For example, this type power window system opens and closes a side window glass of a motor vehicle. The power window system has a remote control unit to input instructions for opening and closing the window glass and an in-vehicle-mounted unit for moving the window glass in response to the instructions of the remote control unit.
FIG. 4 is a flowchart showing process steps of the in-vehicle unit with regard to the power window system. Step S91 of FIG. 4 determines whether a power window (PW) operation signal has been input. When the determination is affirmative, the execution of the system goes to step S92. The PW operation signal is specified in an “up” movement for moving the window glass upward, a “down” movement for moving the window glass downward, or another order for moving the window glass.
Step S92 determines whether the PW operation signal is specified in one of the up and down movements. When the PW operation signal is specified in one of the movements, the execution goes to step S94. Meanwhile, when the PW operation signal is the other order, the execution goes to step S93.
Step S94 determines whether the PW operation signal is specified in an up movement or a down movement. When the PW operation signal is specified in an up movement, the execution goes to step S96 for moving the window glass upward. Meanwhile, when the PW operation signal is specified in a down movement, the execution goes to step S95 for moving the window glass downward.
When the decision of S92 is negative, the execution goes to step S93 that determines whether the window glass is fully closed or not. When the decision is affirmative, the execution goes to step S95 for outputting a down instruction to move the window glass downward. Meanwhile, when the decision is negative, the execution goes to step S96 for outputting an up instruction to move the window glass upward.
A prior art related to the present invention is disclosed in Japanese Patent Application Laid-open No. H-10-250375 or in Japanese Patent Application Laid-open No. 2001-98842.
As disclosed in a prior art disclosed in the latter patent application, some conventional power window systems have a device for preventing pinching of an intervening object during an upward movement of a window glass. The device detects an over current flowing in an electric motor moving the window glass and turns the motor adversely to move the window glass downward. A masking process may have been applied to prevent a wrong reverse turn of the motor due to an over current during a starting period of the motor. Thus, the over current tends to be set at a comparative higher value.
To prevent the wrong reverse turn of the motor, the masking process is applied in a circuit related to the flowchart of FIG. 4. When the window glass is not positioned in a fully closed state, the window glass moves upward in response to a closing signal of an opening and closing instruction switch. Therefore, during the start masking process, the motor does not turn adversely for a short while even when the window glass pinches a finger, a hand, or an arm of a passenger. Accordingly, the conventional power window system employing the single switch must be still improved.